Imaging of Gastrointestinal Bleeding: An Update

Imaging of gastrointestinal bleeding crucial in the diagnosis of occult gastrointestinal bleeding. Gastrointestinal bleeding scintigraphy is a well-established study to aid localisation of gastrointestinal bleeding site. This article discusses about the use of gastrointestinal bleeding scintigraphy in its current practice with emphasis on radiopharmaceutical, imaging techniques, interpretation and pitfalls. There is also discussion on the use of Single Photon Emission Computed Tomography-Computed Tomography (SPECT-CT) within this method of scintigraphy. Meckel's diverticulum is known to be a frequent source of bleeding, mainly in children. It is also know that nuclear medicine imaging can help with Meckel's diverticulum identification. This article also discusses about the technique, imaging, interpretation and SPECT-CT usage for Meckel's diverticulum imaging.

Assessment of variceal bleeding in cirrhotic patients: accuracy of multi-detector computed tomography

Background

Esophageal variceal hemorrhage (EVH) has been shown to be a leading cause of mortality in patients with portal hypertension. Our purpose was to assess the utility of multi-detector computed tomography (MDCT) features in the assessment of esophageal varices (EVs) and esophageal variceal hemorrhage (EVH). This prospective study included 85 cirrhotic patients who underwent MDCT and Upper Gastrointestinal Tract (UGIT) endoscopy within 2 weeks. Four radiologists evaluated the presence of EVs and the presence and size of different collaterals. Multivariable logistic regression analysis was calculated to investigate the significant predictors influencing EV and EVH.

Results

Findings of EV with MDCT were the best predictor of EV or EVH. The presence (and/or size) of following collaterals had significant association with both EV and EVH: paraesophageal (p < 0.001, < 0.001), short gastric (p = 0.024, 0.010), gastric varicosities (p < 0.001, < 0.001), coronary (p < 0.001, < 0.001), and main coronary vein (MCV) (p < 0.001, = 0.011). We proposed an imaging-based model (presence of coronary collaterals, main coronary vein size > 3.5 mm, presence of short gastric collaterals, presence of gastric varicosities, size > 1.5 mm) with 97% sensitivity, 91% specificity, and 94% accuracy to predict EVs. We suggested another model (presence of paraesophageal collaterals, presence of short gastric vein (SGC), SGC size > 2.5 mm, main coronary vein size > 3.5 mm, gastric varicosities size > 1.5 mm, size of EVs > 4 mm, and Child C score) to predict EVH with 98% sensitivity, 81% specificity, and 89.5% accuracy. Inter-observer agreement was high in the detection of EVs (W. Kappa = 0.71–0.88).

Conclusion

MDCT is an effective modality in the diagnosis of EVs. At MDCT, the presence and/or size of various collaterals including para-esophageal, short gastric, coronary collaterals, and gastric varicosities are accurate predictors for either EVs existence or EVH. We suggested two computed tomography imaging-based models with high reproducibility and acceptable accuracy for the prediction of EV and EVH. With cirrhotic patients, we recommend that radiologists report collaterals in their daily practice.

Gastrointestinal bleeding: imaging and interventions in cancer patients

Gastrointestinal bleeding (GIB) among cancer patients is a major source of morbidity and mortality. Although a wide variety of etiologies contribute to GIB, special considerations should be made for cancer-related factors such as the type of malignancy, location and extent of disease, hemostatic parameters, and treatment effects. Key imaging modalities used to evaluate GIB include computed tomography angiography (CTA), radionuclide imaging, and catheter-based angiography. Understanding the cancer and treatment history and recognizing the associated imaging manifestations are important for identifying the source and potential causes of GIB in cancer patients. This article will review the common clinical presentations, causes, imaging manifestations, and angiographic management of GIB in cancer patients.

Esophageal variceal hemorrhage: the role of MDCT characteristics in predicting the presence of varices and bleeding risk

PURPOSE

To investigate the associated Multi-Detector Computed Tomography (MDCT) features for esophageal varices (EVs) and esophageal variceal hemorrhage (EVH), with particular emphasis on different collateral veins.

MATERIALS AND METHODS

All cirrhotic patients who had undergone both Upper Gastrointestinal Tract (UGIT) endoscopy and contrast-enhanced MDCT within 6 months from 2013 to 2019 were included in the study. MDCT of 124 patients, 76 males and 48 females, aged between 21 and 73 years old were evaluated for presence of EV and presence and size of different collaterals. The presence and size of collaterals in patients with high-risk EVs or EVH were compared with others.

RESULTS

Findings of EV in MDCT analysis were the best predictor of EV or EVH, and presence (and/or size) of following collaterals showed a significant relationship with both EV and EVH: coronary (p = 0.006, 0.002), short gastric (SGC) (p = 0.02, < 0.001), and paraesophageal (p = 0.04, 0.01). Those presenting each aforementioned collaterals or with higher collateral size were more likely to develop the EV or EVH. Yet, other collaterals indicated no similar association: para-umbilical, omental, perisplenic, and splenorenal. Main coronary vein (p = 0.02, 0.03) and fundus (p = 0.006, 0.001) varices' sizes were also significantly higher in patients with EV or EVH. Finally, we suggested an imaging-based model (presence of SGC, SGC size > 2.5 mm, presence of EV, and coronary vein size > 3.5 mm) with 75.86% sensitivity, 76.92% specificity, and 76.36% accuracy to predict the presence of EVs according to UGIT endoscopy. Furthermore, we presented another model (presence of SGC, SGC size > 2.5 mm, presence of EV, and MELD score > 11.5 mm) to predict the occurrence of EVH with 75.86% sensitivity, 76.92% specificity, and 76.36% accuracy.

CONCLUSION

We suggested imaging characteristics for predicting EV and EVH with especial emphasis on the presence and size of various collaterals; then, we recommended reliable imaging criteria with high specificity and accuracy for predicting the EV and EVH.

A Jejunal Dieulafoy Lesion: Rare Case Necessitating Surgical Intervention

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Dieulafoy lesions are aberrant submucosal lesions that, in rare circumstances, can result in massive gastrointestinal bleeding.

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These lesions are particularly rare in the jejunum, thus usual diagnostic and therapeutic modalities such as endoscopy may prove difficult.

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Additional imaging such as angiography or radionuclide scanning can be beneficial in identifying the source of bleeding.

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If advanced endoscopic instruments are unavailable at one’s facility, the surgeon must consider operative intervention for life-saving measures.

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The operative findings and management discussed can guide clinicians unexposed to this disease process when surgical intervention is imminent.

Introduction

Dieulafoy lesions are enlarged atypical submucosal vessels that erode the superimposing epithelium in the absence of a primary ulcer. They occur predominantly in the gastric mucosa; however, cases have been seen throughout the gastrointestinal (GI) tract, and rarely, the jejunum. These lesions can cause massive GI hemorrhage leading to shock.

Case Presentation

We present a healthy 19-year-old male who arrived at our institution’s emergency department with multiple episodes of hematemesis and hematochezia that began earlier that morning. The patient was resuscitated and underwent a computerized tomographic (CT) angiography that did not identify any areas of active extravasation. The patient was then taken for an emergent upper and lower endoscopy that was inconclusive. He was subsequently sent for a tagged red blood cell scan, which demonstrated active bleeding in the proximal jejunum. Shortly thereafter, the patient began to decompensate requiring additional blood products and vasopressors. The decision was made for immediate operative intervention, which identified the bleeding Dieulafoy lesion (confirmed by histopathology) in the jejunum.

Discussion

Dieulafoy lesions are rare with an initial presentation of upper or lower GI bleeding, generally treated with endoscopic intervention. They are predominately found in the stomach or duodenum. When no clear source is identified by endoscopy, further diagnostic testing may be of value. Various imaging modalities exist; however, CT angiography or radionuclide scanning are particularly sensitive and can be beneficial in localizing the bleed when preparing for operative intervention.

Conclusion

With advances in endoscopic techniques, surgical intervention is rarely performed for a Dieulafoy lesion. If endoscopy is unsuccessful, additional imaging can be obtained to localize the source of bleeding. However, in emergent cases, when additional imaging cannot be obtained due to lack of time or resources, adequate resection of the lesion should be performed for complete resolution of the disease process. Based on the case presentation and pathologic findings, this case provides further insight into Dieulafoy lesions and the rare need for surgical management.

Small bowel gastrointestinal stromal tumor: a retrospective study of 32 cases at a single center and review of the literature

Background

Gastrointestinal stromal tumor (GIST) is a rare tumor of the small bowel, which can be difficult to diagnose and has a varied clinical outcome.

Purpose

This is a retrospective review of the diagnosis, management, and clinical outcome of 32 patients diagnosed with primary small bowel GIST from a single center and a comparison of the findings with previously published cases.

Patients and methods

Retrospective review of data from patient clinical records, endoscopic and imaging findings, surgical procedures, tumor histology and immunohistochemistry, and clinical outcome was conducted.

Results

Data of 32 patients with a median age of 56 years including 50% men and women were reviewed. The majority (29/32) were symptomatic at presentation, with the main symptom being gastrointestinal bleeding (15/32). Imaging detection rates included ultrasound (0%), magnetic resonance imaging (0%), computed tomography (54.8%), computed tomography angiography (71.4%), and double-balloon enteroscopy (88.9%). The mean tumor diameter was 5.3 cm; 4 tumors were located in the duodenum, 21 in the jejunum, and 7 in the ileum. Based on the tumor size and mitotic index, 5 (15.6%), 15 (46.9%), 0 (0%), and 12 (37.5%) patients were classified into very low-risk, low-risk, intermediate-risk, and high-risk groups. Immunohistochemistry showed positive expression for CD117 (100%), CD34 (81.2%), DOG1 (93.8%), smooth muscle actin (37.5%), S100 (9.4%), and desmin (6.2%). Twenty-five patients (78.1%) were treated with open surgical tumor resection; seven patients (21.9%) underwent laparoscopic surgery. Postoperative complications that occurred in seven patients (21.9%) were resolved with conservative management. Four patients were treated with postoperative imatinib. At median follow-up of 30 months, two patients were died.

Conclusion

The findings from this case series, combined with the findings from previously published cases, provide an update on the current status of the diagnosis and the therapeutic approaches that might lead to improvement in prognosis for patients who present with primary small bowel GIST.

Practical Applications of Dual-Energy Computed Tomography in the Acute Abdomen

With new developments in workflow automation, as well as technological advances enabling faster imaging with improved image quality and dose profile, dual-energy computed tomography is being used more often in the imaging of the acutely ill and injured patient. Its ability to identify iodine, differentiate it from hematoma or calcification, and improve contrast resolution has proven invaluable in the assessment of organ perfusion, organ injury, and inflammation.

Iron deficiency anaemia in a coeliac: a cause for concern?

A 70-year-old woman with a 15-year history of coeliac disease was admitted for treatment and investigation of symptomatic anaemia. Of note, she was recently commenced on aspirin therapy for retinal artery occlusion. This followed a normal gastro-duodenoscopy, colonoscopy and CT abdomen as workup for iron deficiency anaemia. On this occasion, the patient was further investigated with small bowel capsule endoscopy. This revealed an ulcerated lesion in her proximal jejunum suspicious for malignancy, namely lymphoma. A biopsy of the lesion confirmed adenomatous changes and high-grade dysplasia without malignant changes. Given the endoscopic appearances of the lesion, she was further evaluated with a small bowel MRI. This revealed a 3 cm lesion with associated lymphadenopathy but no distant metastases. She proceeded to resection of her small bowel which confirmed an invasive adenocarcinoma of her proximal jejunum. She is currently undergoing adjuvant chemotherapy on an outpatient basis.

Impact of CT enterography on the diagnosis of small bowel gastrointestinal stromal tumors

OBJECTIVE

Our purpose is to determine the impact of CT enterography on small bowel gastrointestinal stromal tumor (GIST) detection and biologic aggressiveness, and to identify any imaging findings that correlate with biologic aggressiveness.

METHODS

Records of patients with histologically confirmed small bowel GISTs who underwent CT imaging were reviewed. Biologic aggressiveness was based on initial histologic grading (very low, low, intermediate, high grade; or malignant), with upgrade to malignant category if local or distant metastases developed during clinical follow-up. Imaging indications, findings, and type of CT exam were compared with the biologic aggressiveness.

RESULTS

111 small bowel GISTs were identified, with suspected small bowel bleeding being the most common indication (45/111; 40.5%). While the number of malignant GISTs diagnosed by CT remained relatively constant (2-3 per year), the number of non-malignant GISTs increased substantially (mean 1.5/year, 1998-2005; 8.4/year, 2006-2013). In patients with suspected small bowel bleeding, CT enterography identified 33 GISTs (7/33, 21% malignant) compared to 12 GISTs by abdominopelvic CT (6/12, 50% malignant; p < 0.03). Tumor size (p < 0.0001), internal necrosis (p = 0.005), internal air or enteric contrast (p ≤ 0.021), and ulceration (p ≤ 0.021) were significantly associated with high-grade and malignant tumors, and irregular or invasive tumor borders (p < 0.01) was associated with malignant tumors.

CONCLUSION

The detection of small bowel GISTs can increase due to the use of CT enterography in patients with suspected small bowel bleeding. The large majority of small bowel GISTs detected by CT enterography are not malignant.

Comparison of patients' tolerance between computed tomography enterography and double-balloon enteroscopy

BACKGROUND

Computed tomography enterography (CTE) and double-balloon enteroscopy (DBE) are widely used in diagnosis of small bowel diseases. Both of these examinations bring discomfort to patients. The aim of this study was to compare patients' tolerance and preference between CTE and DBE.

METHODS

From August 1, 2014 to December 31, 2016, patients with suspected or known small bowel diseases who underwent both CTE and DBE were prospectively enrolled in our study. They were asked to fill out a questionnaire evaluating discomfort of the procedure after each examination.

RESULTS

One hundred and seven patients completed our study. Abdominal distension, painfulness, tenesmus, general discomfort, prolonged duration, difficulty in completing the test, and discomfort after the examination were significantly lower with CTE than with DBE (P<0.001, respectively). Mannitol intake (47.7%), bowel preparation (31.9%), and radiation exposure (15.0%) were regarded as the three most intolerable burdens in CTE. Painfulness (38.3%), bowel preparation (26.2%), and invasiveness (16.8%) were considered as the three most unacceptable parts of DBE. More patients (61.7%) preferred to repeat CTE rather than DBE (P<0.001).

CONCLUSION

Compared to DBE, CTE was a more tolerable and less burdensome examination and enjoyed higher preference by most patients.

[Clinical Efficacy of Dynamic Contrast-enhanced Multidetector-row Computed Tomography in Patients with Obscure Gastrointestinal Bleeding]

BACKGROUND/AIMS

Obscure gastrointestinal bleeding (OGIB) accounts for 5% of all gastrointestinal (GI) bleeding cases. Dynamic contrast-enhanced multidetector-row CT (DCE-MDCT) is not generally recommended in OGIB patients due to its low sensitivity. However, it can be used to quickly and simply diagnose OGIB according to some guidelines. The aim of this study was to evaluate the clinical efficacy of DCE-MDCT in OGIB patients.

METHODS

We retrospectively analyzed the medical records of 362 patients who underwent DCE-MDCT between March 2009 and January 2014. A total of 45 patients diagnosed with OGIB were included in this study. Their baseline characteristics and treatment procedure were analyzed retrospectively. The positive rates of DCE-MDCT for the detection of bleeding and associated factors were assessed.

RESULTS

The mean age of the patients was 59 years, and males represented 51.1%. Melena was the most common symptom (44.4%). Positive rate of DCE-MDCT findings was 20.0% (9/45). Among these patients, intraluminal contrast extravasation was found in 5 patients (55.6%) and intraluminal hematoma or mass lesions were found in 2 patients each (22.2%). Thirty nine patients (86.7%) underwent conservative management, and 6 patients (13.3%) underwent specific treatment, such as endoscopic treatment, embolization, or surgery. Patients who showed positivity in DCE-MDCT more frequently received specific treatment compared with those who were negative (44.4% vs. 5.6%, p=0.010).

CONCLUSIONS

Although DCE-MDCT showed a low positive rate (20.0%), positive findings of DCE-MDCT could lead to specific treatment. Positive DCE-MDCT findings play a useful role in the management of patients with OGIB.

CT enterography: technical and interpretive pitfalls

CT enterography is a first-line test at many institutions to investigate potential small bowel disorders. While numerous articles have focused on the ability of CT enterography to diagnose and stage Crohn's disease, small bowel neoplasia, and malabsorptive or vascular disorders, this article reviews CT enterography limitations, technical and interpretive pitfalls, image review tactics, and complementary radiologic and endoscopic examinations to improve diagnostic accuracy. CT enterography limitations include its inability to demonstrate isolated mucosal abnormalities such as aphthous ulcers and its use of ionizing radiation. The most common technical pitfall of CT enterography is inadequate small bowel distention resulting from inadequate ingestion, gastric retention, or rapid small bowel transit of a large volume of neutral enteric contrast material. Additionally, segments of jejunum are frequently collapsed. Interpretive pitfalls commonly result from peristaltic contractions, transient intussusception and opaque intraluminal debris. Opaque debris is especially problematic during multiphasic CT enterography performed to identify potential small bowel sources of obscure gastrointestinal bleeding. False-negative examinations may result from inadequate radiation dose. Examinations complementary to CT enterography include small bowel follow through, enteroclysis, CT enteroclysis, MR enterography, MR enteroclysis, capsule endoscopy, and balloon-assisted endoscopy. Properly performed and accurately interpreted CT enterography contributes to the diagnosis and management of small bowel disease by itself and as a complement to other radiologic and optical small bowel imaging examinations.

Computed tomography angiography in patients with active gastrointestinal bleeding

Gastrointestinal bleeding represents a common medical emergency, with considerable morbidity and mortality rates, and a prompt diagnosis is essential for a better prognosis. In such a context, endoscopy is the main diagnostic tool; however, in cases where the gastrointestinal hemorrhage is massive, the exact bleeding site might go undetected. In addition, a trained professional is not always present to perform the procedure. In an emergency setting, optical colonoscopy presents limitations connected with the absence of bowel preparation, so most of the small bowel cannot be assessed. Scintigraphy cannot accurately demonstrate the anatomic location of the bleeding and is not available at emergency settings. The use of capsule endoscopy is inappropriate in the acute setting, particularly in the emergency department at night, and is a highly expensive method. Digital angiography, despite its high sensitivity, is invasive, presents catheterization-related risks, in addition to its low availability at emergency settings. On the other hand, computed tomography angiography is fast, widely available and minimally invasive, emerging as a promising method in the diagnostic algorithm of these patients, being capable of determining the location and cause of bleeding with high accuracy. Based on a critical literature review and on their own experience, the authors propose a computed tomography angiography protocol to assess the patient with gastrointestinal bleeding.

Diagnosis and treatment of Crohn's disease complicated by massive lower gastrointestinal hemorrhage

Crohn's Disease (CD) is a chronic granulomatous inflammatory disorder of the gastrointestinal tract. With the change of the life style and the progress of the diagnosis method, the number of patients diagnosed with CD has increased in China. In the course of disease development, some patients may have intestinal obstruction, abdominal abscess, acute perforation, gastrointestinal bleeding or other complications. Massive lower gastrointestinal hemorrhage is not a common complication of CD, and is a challenge for diagnosis and therapeutic management. It is more difficult to diagnose and treat CD associated lower digestive tract hemorrhage, compared with massive hemorrhage of lower digestive tract caused by other reasons. This paper reviews recent advances in the diagnosis and management of CD complicated with severe lower gastrointestinal hemorrhage.

Real-time fluorescence angiography by intra-arterial indocyanine green injection to identify obscure gastrointestinal bleeding territory: proof of concept in the porcine model

BACKGROUND

Despite intensive preoperative localization workouts, intraoperative localization of the bleeding source in case of obscure gastrointestinal bleeding (OGIB) can be cumbersome and time-consuming. Our aim was to assess the feasibility of image-guided laparoscopic identification of the small bowel loop containing the bleeding source with and without near-infrared angiographic enhancement.

MATERIALS AND METHODS

Angiography of superior mesenteric artery (SMA) branches was performed in 11 pigs using a right femoral artery approach, followed by a three-port laparoscopy, using a near-infrared-equipped laparoscope. Two pigs were used to identify the optimal intra-arterial indocyanine green (ICG) dose. Eight pigs were divided into two groups: ICG near-infrared angiography-assisted laparoscopy (n = 4) and fluoroscopic-assisted laparoscopy (n = 4). Finally, in one pig, a novel OGIB model was created and used to evaluate the ICG enhancement pattern in the presence of active bleeding.

RESULTS

Mean time to identify the fluorescence signal from the small bowel segment fed by the catheterized SMA branch was 13.75 ± 7.8 s, which was statistically significantly shorter than the time required to identify the tip of the catheter by fluoroscopic guidance, i.e., 243.25 ± 107 s (p = 0.02).

CONCLUSIONS

Near-infrared fluorescence angiography using intra-arterial ICG injection provides a fast image-guided intraoperative localization of the small bowel loop fed by the arterial territory identified as bleeding by digital subtraction angiography and could help target the bleeding source during OGIB surgery.

Beneficial effects of combining computed tomography enteroclysis/enterography with capsule endoscopy for screening tumor lesions in the small intestine

Aim. To compare the efficacy of using computed tomography enteroclysis/enterography (CTE), capsule endoscopy (CE), and CTE with CE for diagnosing tumor lesions in the small intestine. Materials and Methods. We included 98 patients who underwent CE during the observation period and were subjected to CTE at our hospital from April 2008 to May 2014. Results. CTE had a significantly higher sensitivity than CE (84.6% versus 46.2%, P = 0.039), but there were no significant differences in specificity, positive or negative predictive values, or diagnostic accuracy rates. The sensitivity of CTE/CE was 100%, again significantly higher than that of CE (P = 0.002). The difference in specificity between CTE/CE and CE was not significant, but there were significant differences in positive predictive values (100% for CTE/CE versus 66.7% for CE, P = 0.012), negative predictive values (100% versus 92.1%, P = 0.008), and diagnostic accuracy rate (100% versus 89.8%, P = 0.001). The diagnostic accuracy rate was also significantly higher in CTE/CE versus CTE (100% versus 95.9%, P = 0.043). Conclusion. Our findings suggested that a combination of CTE and CE was useful for screening tumor lesions in the small intestine. This trial is registered with number UMIN000016154.

Protein C deficiency related obscure gastrointestinal bleeding treated by enteroscopy and anticoagulant therapy

Obscure gastrointestinal bleeding is an uncommonly encountered and difficult-to-treat clinical problem in gastroenterology, but advancements in endoscopic and radiologic imaging modalities allow for greater accuracy in diagnosing obscure gastrointestinal bleeding. Ectopic varices account for less than 5% of all variceal bleeding cases, and jejunal variceal bleeding due to extrahepatic portal hypertension is rare. We present a 47-year-old man suffering from obscure gastrointestinal bleeding. Computed tomography of the abdomen revealed multiple vascular tufts around the proximal jejunum but no evidence of cirrhosis, and a visible hypodense filling defect suggestive of thrombus was visible in the superior mesenteric vein. Enteroscopy revealed several serpiginous varices in the proximal jejunum. Serologic data disclosed protein C deficiency (33.6%). The patient was successfully treated by therapeutic balloon-assisted enteroscopy and long-term anticoagulant therapy, which is normally contraindicated in patients with gastrointestinal bleeding. Diagnostic modalities for obscure gastrointestinal bleeding, such as capsule endoscopy, computed tomography enterography, magnetic resonance enterography, and enteroscopy, were also reviewed in this article.

Evaluation of gastrointestinal bleeding: Update of current radiologic strategies

Gastrointestinal bleeding (GIB) is a common presentation with significant associated morbidity and mortality, the prevalence of which continues to rise with the ever-increasing aging population. Initial evaluation includes an esophagoduodeonscopy and/or colonoscopy, which may fail to reveal a source. Such cases prove to be a dilemma and require collaboration between gastroenterology and radiology in deciding the most appropriate approach. Recently, there have been a number of radiologic advances in the approach to GIB. The purpose of this review is to provide an evidence-based update on the most current radiologic modalities available and an algorithmic approach to GIB.

Obscure gastrointestinal bleeding: diagnostic performance of 64-section multiphase CT enterography and CT angiography compared with capsule endoscopy

OBJECTIVE

To compare the diagnostic capabilities between capsule endoscopy (CE) and multislice CT (MSCT) enterography in combination with MSCT angiography for assessment of obscure gastrointestinal bleeding (OGIB).

METHODS

A total of 127 patients with OGIB were looked at in this study. 82 patients (aged 42.7 ± 19.1 years; 34 males) were assigned to receive MSCT diagnosis and 67 patients to (aged 53.9 ± 16.2 years; 28 males) receive CE diagnosis. Among them, 22 patients (aged 54.1 ± 19.1 years; 12 males) received both examinations. Oral isotonic mannitol and intramuscular injection of anisodamine were performed; non-ionic contrast (iopromide, 370 mg I ml(-1)) was intravenously administered; and then multiphase scanning was conducted at arterial, small intestinal and portal venous phases in MSCT. The results were compared with findings of reference standards including double balloon enteroscopy, digital subtraction angiography, intraoperative pathological examination and/or clinical diagnosis.

RESULTS

Administration of anisodamine markedly increased the satisfaction rate of bowel filling (94.67% vs 28.57%; p < 0.001) but not the diagnostic yield (p = 0.293) of MSCT. Compared with MSCT, CE showed an improved overall diagnostic yield (68.66% vs 47.56%; p = 0.010), which was also observed in overt bleeding patients (i.e. patients with continued passage of visible blood) (76.19% vs 51.02%; p = 0.013) and in patients aged younger than 40 years of age (85% vs 51.28%; p = 0.024). However, CE had similar positive rates to MSCT (p > 0.05). Among the 22 cases in whom both examinations were conducted, CE showed no significantly different diagnostic capability compared with MSCT (p = 0.4597).

CONCLUSION

Both CE and MSCT are safe and effective diagnostic methods for OGIB.

ADVANCES IN KNOWLEDGE

CE is preferred for overt bleeding or patients aged younger than 40 years. The combined use of CE and MSCT is recommended in OGIB diagnosis.

New insights to occult gastrointestinal bleeding: From pathophysiology to therapeutics

Obscure gastrointestinal bleeding is still a clinical challenge for gastroenterologists. The recent development of novel technologies for the diagnosis and treatment of different bleeding causes has allowed a better management of patients, but it also determines the need of a deeper comprehension of pathophysiology and the analysis of local expertise in order to develop a rational management algorithm. Obscure gastrointestinal bleeding can be divided in occult, when a positive occult blood fecal test is the main manifestation, and overt, when external sings of bleeding are visible. In this paper we are going to focus on overt gastrointestinal bleeding, describing the physiopathology of the most usual causes, analyzing the diagnostic procedures available, from the most classical to the novel ones, and establishing a standard algorithm which can be adapted depending on the local expertise or availability. Finally, we will review the main therapeutic options for this complex and not so uncommon clinical problem.

Evaluation and management of small-bowel tumors in the era of deep enteroscopy

In summary, small-intestine tumors are a rare phenomenon, but they are being discovered more frequently with newer diagnostic techniques. Prior studies of the small bowel were limited, making the diagnosis difficult. With the advent of CE and deep enteroscopy, gastroenterologists are finding these tumors at an earlier stage, thereby offering better management options for these patients. Although the incidence of small-bowel tumors has increased, the survival rates have remained the same. This may be a lag-time bias but could be a future area of research in this emerging field.

Multidetector CT oesophagography: an alternative screening method for endoscopic diagnosis of oesophageal varices and bleeding risk

BACKGROUND AND STUDY AIMS

Variceal bleeding is a frequent and life-threatening complication of portal hypertension. The aim of this study was to evaluate multidetector computed tomographic (MDCT) oesophagography as an alternative to endoscopy for screening oesophageal varices (EVs) and predicting bleeding risk.

PATIENTS AND METHODS

A total of 137 cirrhotic patients underwent MDCT followed by endoscopy and EVs were graded independently. The screening ability of CT for EV was evaluated by comparing the grades of EV at CT and at endoscopy. Prediction of bleeding risk by CT was determined by correlating the CT variceal grades, diameters and palisade vein dilatation with the endoscopic red colour (RC) sign. Extra-oesophageal findings were assessed by CT. Patients' acceptance for both examinations were compared.

RESULTS

At endoscopy, 47 (34%) patients had grade 0 EV, 52 (38%) patients had grade 1 EV, 29 (21%) patients had grade 2 EV and nine (7%) patients had grade 3 EV. The sensitivity, specificity, positive and negative predictive values and accuracy of CT oesophagography for defining EV in all grades were 99%, 98%, 99%, 98% and 99%, respectively. The MDCT variceal grades, diameters and palisade vein dilatation were correlated with the severity of the RC sign. Important extra-oesophageal findings were determined by CT only. The acceptance of patients for CT oesophagography was significantly more than that for endoscopy (p<0.001).

CONCLUSION

MDCT is a reliable, preliminary or adjunctive method that can be used for routine screening for EVs and the prediction of variceal bleeding.

Comparison of MR enteroclysis with video capsule endoscopy in the investigation of small-intestinal disease

Purpose

To evaluate the diagnostic accuracy of MR enteroclysis and to compare it to video capsule endoscopy (VCE) in the analysis of suspected small-bowel disease.

Methods

We performed a retrospective analysis of 77 patients who underwent both MR enteroclysis and VCE and compared the findings of these studies with the findings of enteroscopy, surgery, or with the results of clinical follow-up lasting ≥2 years.

Results

Findings included malignant neoplasms (n = 13), benign neoplasms (n = 10), refractory celiac disease (n = 4), Crohn’s disease (n = 2) and miscellaneous conditions (n = 10). Specificity of MR enteroclysis was higher than that of VCE (0.97 vs. 0.84, P = 0.047), whereas sensitivity was similar (0.79 vs. 0.74, P = 0.591). In 2/32 (6.3%) patients with both negative VCE and negative MR enteroclysis a positive diagnosis was established, compared to 5/11 (45.5%) patients in whom VCE was positive and MR enteroclysis was negative (likelihood ratio 8.1; P = 0.004), 9/11 (81.8%) patients in whom MR enteroclysis was positive and VCE was negative (likelihood ratio 23.5; P < 0.0001), and all 23 patients in whom both VCE and MR enteroclysis showed abnormalities (likelihood ratio 60.8; P < 0.0001).

Conclusions

VCE and MR enteroclysis are complementary modalities. In our study-population, MR enteroclysis was more specific than VCE, while both produced the same sensitivity.

CT enterography in obscure gastrointestinal bleeding: a systematic review and meta-analysis

The objective of this article is to provide a comprehensive and update overview of clinical application of CT enterography (CTE) in the evaluation of obscure gastrointestinal bleeding (OGIB). We performed a systematic review of relevant literatures in PubMed, EMBASE and The Cochrane Library and pooled the yield of CTE and the incremental yield (IY) of CTE over an alternate modality. A total of 18 studies (n = 660) reported the yield of CTE in evaluating OGIB and the pooled yield was 40% (95% confidence interval (CI): 33-49%). Seven studies (n = 279) compared the yield of CTE with capsule endoscopy (CE). The yield for CTE and CE for all findings was 34% and 53%, respectively (IY = -19%, 95% CI = -34% to -4%). When considering the types of identified lesions, the yield was significantly different for vascular and inflammatory lesions but not significantly different for neoplastic or other lesions. Two studies (n = 63) compared the yield of CTE with double-balloon enteroscopy (DBE). The yield for CTE and DBE was 38% and 78%, respectively (IY = -40%, 95% CI = -55% to -25%). Three studies (n = 49) compared the yield of CTE with digital subtraction angiography. The yield for CTE and digital subtraction angiography was 64% and 60%, respectively (IY = 4%, 95% CI = -40% to 47%). CTE is an excellent diagnostic tool in patients with OGIB. It may play a complementary role to CE and can be used as a triage tool prior to DBE in evaluating OGIB.

Use of CT enterography for the diagnosis of lower gastrointestinal bleeding in pediatric patients

Diagnosis of lower gastrointestinal bleeding (LGIB) represents a significant diagnostic and therapeutic challenge for any physician. While CT enterography (CTE) has been applied in adults with occult LGIB, its use in children has been limited to evaluation of Crohn's disease. We reviewed 6 patients ages 4-15 who underwent CTE for LGIB at a tertiary pediatric institution. In sum, CTE appears to be a valuable tool for localizing the source of LGIB prior to surgical or endoscopic intervention. However, rapid lesion identification must be weighed against the increased radiation exposure and patient discomfort due to bowel distention associated with this diagnostic technique.

Endoscopic and radiographic evaluation of the small bowel in 2012

Traditionally, the diagnosis of small bowel disorders has been challenging secondary to the small intestine's length, tortuosity, and anatomic location. Recent technologic advancements in the field of enteroscopy and radiographic imaging have facilitated a more thorough endoscopic evaluation of patients with small bowel disease ranging from obscure gastrointestinal bleeding to inflammatory bowel disease and small bowel tumors. Such developments have made it possible to avoid invasive surgical procedures in certain clinical scenarios where they were previously the gold standard. In this review, we report an update on the diagnostic and management approach to patients with small bowel disease, emphasizing the advantages and limitations of the latest modalities now available to primary care physicians and gastroenterologists for evaluating patients with presumed disease of the small intestine.

Uncommon causes of acute abdominal pain: multidetector computed tomography pearls and pitfalls for the radiologist on call

We review uncommon causes of acute abdominal pain in which inconclusive multidetector computed tomography (MDCT) studies were followed by emergency surgery and unexpected diagnoses. Despite dedicated protocols and technical advances, MDCT of uncommon causes of acute abdominal pain still represents a significant challenge for the radiologist on call. We emphasize diagnostic pearls and pitfalls that may help the radiologist on call identify or suspect these uncommon causes of acute abdominal pain on MDCT.

Small bowel diagnostics: current place of small bowel endoscopy

The small intestine has been difficult to examine by traditional endoscopic and radiologic techniques. Until the end of the last century, the small bowel follow through was the primary diagnostic tool for suspected small bowel disease. In recent years capsule endoscopy, deep enteroscopy using balloon-assisted or spiral techniques, computerized tomography and magnetic resonance enteroclysis or enterography have facilitated the diagnosis, monitoring, and management of patients with small bowel diseases. These technologies are complementary, each with its advantages and limitations. In the present article, we will discuss the different options and indications for modern diagnostic methods for visualization of the small bowel. We also try to provide a clinical rationale for the use of these different diagnostic options in less established, newly emerging, indications for small bowel evaluation.

Obscure and occult gastrointestinal bleeding: comparison of different imaging modalities

Patients with persistent, recurrent, or intermittent bleeding from the gastrointestinal (GI) tract for which no definite cause has been identified by initial esophagogastroduodenoscopy, colonoscopy, or conventional radiologic evaluation are considered to have an obscure GI bleeding (OGIB). The diagnosis and management of patients with OGIB is challenging, often requiring extensive and expensive workups. The main objective is the identification of the etiology and site of bleeding, which should be as rapidly accomplished as possible, in order to establish the most appropriate therapy. The introduction of capsule endoscopy and double balloon enteroscopy and the recent improvements in CT and MRI techniques have revolutionized the approach to patients with OGIB, allowing the visualization of the entire GI tract, particularly the small bowel, until now considered as the "dark continent" . In this article we review and compare the radiologic and endoscopic examinations currently used in occult and OGIB, focusing on diagnostic patterns, pitfalls, strengths, weaknesses, and value in patients' management.

Clinical impact of multidetector computed tomography before double-balloon enteroscopy for obscure gastrointestinal bleeding

AIM: To evaluate the clinical impact of multidetector computed tomography (MDCT) before double-balloon endoscopy (DBE) for patients with obscure gastrointestinal bleeding (OGIB).

METHODS: A retrospective analysis of prospectively collected cases with DBE and MDCT for overt OGIB was conducted from April 2004 to April 2010 at Changhua Christian Hospital. We evaluated the clinical impact of MDCT on the subsequent DBE examinations and the diagnostic yields of both MDCT and DBE respectively.

RESULTS: From April 2004 to April 2010, a total of 75 patients underwent DBE for overt OGIB. Thirty one cases received MDCT followed by DBE for OGIB. The overall diagnostic yields of DBE and MDCT was 93.5% and 45.2%. The MDCT had a high diagnostic yield of tumor vs non-tumor etiology of OGIB (85.7% vs 33.3%, P = 0.014). Additionally, the choice of initial route of DBE was correct in those with a positive MDCT vs negative MDCT (100% vs 52.9%, P = 0.003).

CONCLUSION: This study suggests MDCT as a triage tool may identify patients who will benefit from DBE and aid the endoscopist in choosing the most efficient route.

The role of capsule endoscopy after negative CT enterography in patients with obscure gastrointestinal bleeding

OBJECTIVES

The aim of the present study was to evaluate the role of capsule endoscopy in patients with obscure gastrointestinal bleeding (OGIB) after negative computed tomographic (CT) enterography.

METHODS

We retrospectively included 30 patients with OGIB who received capsule endoscopy after negative CT enterography. The median age of the patients was 60 years, and 60% of patients were male. The median follow-up duration was 8 months. Overt bleeding was 60%, and occult bleeding was 40%.

RESULTS

Based on capsule endoscopy results, a definitive diagnosis was made for 17 patients (57%): ulcer in nine patients (30%), active bleeding with no identifiable cause in five (17%), angiodysplasia in two (7%) and Dieulafoy's lesion in one (3%). Two patients with jejunal ulcers were diagnosed with Crohn's disease. Seven patients (41%) with positive capsule endoscopy received double balloon enteroscopy and two patients (12%) received steroid treatment for Crohn's disease. Patients with overt bleeding, a previous history of bleeding, or who received large amounts of blood transfusions were more likely to show positive capsule endoscopy.

CONCLUSIONS

Capsule endoscopy showed high diagnostic yields in patients with OGIB after negative CT enterography and may help to provide further therapeutic plans for patients with OGIB and negative CT enterography.

KEY POINTS

• CT enterography has been widely used in evaluating obscure gastrointestinal bleeding (OGIB). • Capsule endoscopy showed high diagnostic yield for OGIB after negative CT enterography. • Negative CT enterography does not exclude important causes of small bowel bleeding. • Most lesions missed at CT-enterography are flat and can be detected by capsule endoscopy.

Multidetector CT angiography in acute gastrointestinal bleeding: why, when, and how

Acute gastrointestinal (GI) bleeding remains an important cause of emergency hospital admissions, with substantial related morbidity and mortality. Bleeding may relate to the upper or lower GI tract, with the dividing anatomic landmark between these two regions being the ligament of Treitz. The widespread availability of endoscopic equipment has had an important effect on the rapid identification and treatment of the bleeding source. However, the choice of upper or lower GI endoscopy is largely dictated by the clinical presentation, which in many cases proves misleading. Furthermore, there remains a large group of patients with negative endoscopic results or failed endoscopy, in whom additional techniques are required to identify the source of GI bleeding. Multidetector computed tomography (CT) with its speed, resolution, multiplanar techniques, and angiographic capabilities allows excellent visualization of both the small and large bowel. Multiphasic multidetector CT allows direct demonstration of bleeding into the bowel and is helpful in the acute setting for visualization of the bleeding source and its characterization. Thus, multidetector CT angiography provides a time-efficient method for directing and planning therapy for patients with acute GI bleeding. The additional information provided by multidetector CT angiography before attempts at therapeutic angiographic procedures leads to faster selective catheterization of bleeding vessels, thereby facilitating embolization. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.313105206/-/DC1.

[Gastrointestinal bleeding: the role of radiology]

Gastrointestinal bleeding represents a diagnostic challenge both in its acute presentation, which requires the point of bleeding to be located quickly, and in its chronic presentation, which requires repeated examinations to determine its etiology. Although the diagnosis and treatment of gastrointestinal bleeding is based on endoscopic examinations, radiological studies like computed tomography (CT) angiography for acute bleeding or CT enterography for chronic bleeding are becoming more and more common in clinical practice, even though they have not yet been included in the clinical guidelines for gastrointestinal bleeding. CT can replace angiography as the diagnostic test of choice in acute massive gastrointestinal bleeding, and CT can complement the endoscopic capsule and scintigraphy in chronic or recurrent bleeding suspected to originate in the small bowel. Angiography is currently used to complement endoscopy for the treatment of gastrointestinal bleeding.

Review article: the diagnosis and investigation of obscure gastrointestinal bleeding

BACKGROUND

Obscure gastrointestinal bleeding (OGIB) is a commonly encountered clinical problem in gastroenterology and is associated with significant morbidity and mortality. The investigation and management of OGIB has changed dramatically over the past decade with the advent of newer gastroenterological and radiological technologies.

AIM

To review the current evidence on the diagnosis and investigation of OGIB.

METHODS

We searched the PubMed database (1985-2010) for full original articles in English-language journals relevant to the investigation of OGIB. The search terms we used were 'gastrointestinal bleeding' or 'gastrointestinal hemorrhage' or 'small bowel bleeding' each in combination with 'obscure', or 'capsule endoscopy', or 'enteroscopy' or 'enterography' or 'enteroclysis'.

RESULTS

Capsule endoscopy (CE) or double balloon enteroscopy (DBE) should be first line investigations. They are complimentary procedures with comparable high diagnostic yields. DBE is also able to provide therapeutic intervention. Newer technologies such as single balloon and spiral enteroscopy are currently being evaluated. Radiological and nuclear medicine investigations, such as CT enterography and CT enteroclysis, are alternative diagnostic tools when CE or DBE are contraindicated. Repeating the gastroscopy and/or colonoscopy may be considered in selective situations. An algorithm for investigation of obscure bleeding is proposed.

CONCLUSIONS

The development of capsule endoscopy and double balloon enteroscopy has transformed the approach to the evaluation and management of obscure gastrointestinal bleeding over the past decade. Older diagnostic modalities still play a complementary, but increasingly selective role.

Diagnosis of acute gastrointestinal bleeding: comparison of the arterial, the portal, and the combined set using 64-section computed tomography

OBJECTIVES

To compare the respective capabilities of the arterial, the portal, and the combined set in the detection and localization of acute gastrointestinal (GI) bleeding with 64-section computed tomography (CT).

METHODS

A total of 46 patients with acute GI bleeding and who had undergone both 64-section CT and digital subtraction angiography were included in this study. The results of angiography were used as a reference standard. Two radiologists independently reviewed the 3 sets of CT images (arterial set, the unenhanced and arterial-phase images; portal set, the unenhanced and portal venous-phase images; combined set, the unenhanced and arterial-phase and portal venous-phase images). The diagnostic accuracy was assessed by a receiver operating characteristic analysis.

RESULTS

For each observer, the Az values were 0.915 and 0.931 for the arterial set, 0.903 and 0.933 for the portal set, and 0.919 and 0.911 for the combined set, respectively. The differences were not statistically significant among the 3 data sets for each observer (P > 0.05). Both observers correctly detected the bleeding site in 81.3% and 84.4% on the arterial set, in 81.3% and 84.4% on the portal set, and in 84.4% and 84.4% on the combined set, respectively.

CONCLUSIONS

Using 64-section CT, the diagnostic performance was not different among the arterial, the portal, and the combined set for the detection and localization of acute GI bleeding.

Imaging of malignant neoplasms of the mesenteric small bowel: new trends and perspectives

This article describes the recent advances in radiological imaging of malignant neoplasms of the mesenteric small bowel and provides an outline of new trends and perspectives that can be anticipated. The introduction of multidetector row technology, which allows the acquisition of submillimeter and isotropic voxels, has dramatically improved the capabilities of computed tomography in the investigation of the mesenteric small bowel. This technology combined with optimal filling of small bowel loops through the use of appropriate enteral contrast agents has markedly changed small bowel imaging. Computed tomography-enteroclysis, which is based on direct infusion of enteral contrast agent into the mesenteric small bowel through a naso-jejunal tube, provides optimal luminal distension. By contrast, computed tomography-enterography is based on oral administration of enteral contrast agent. These two techniques are now well-established ones for the detection and the characterization of small bowel neoplasms. During the same time, combining the advantages of unsurpassed soft tissue contrast and lack of ionizing radiation, magnetic resonance imaging has gained wide acceptance for the evaluation of patients with suspected small bowel neoplasms. Rapid magnetic resonance imaging sequences used in combination with specific enteral contrast agents generate superb images of the mesenteric small bowel so that magnetic resonance-enteroclysis and magnetic resonance-enterography are now considered as effective diagnostic tools for both the detection and the characterization of neoplasms of the mesenteric small bowel. Recent improvements in image post-processing capabilities help obtain realistic three-dimensional representations of tumors and virtual enteroscopic views of the small bowel that are useful for the surgeon and the gastroenteroenteologist to plan surgical or endoscopic interventions. Along with a better knowledge of the potential and limitations of wireless capsule endoscopy and new endoscopic techniques, these recent developments in radiological imaging reasonably suggest that substantial changes in the investigation of small bowel tumors may be anticipated in a near future, thus potentially create a new paradigm shift after standard small bowel follow-through study has been universally abandoned.

Computed tomography of complicated Meckel's diverticulum in adults: a pictorial review

OBJECTIVE: To show various CT aspects of complicated Meckel's diverticulum in adult patients to facilitate the preoperative diagnosis of this rare pathology in emergency settings. METHODS: A computer search of medical records over a 15 year period identified 23 adult patients who underwent surgery for acute abdomen generated by a complicated Meckel's diverticulum. CT images available for review were analyzed, and some specific patterns leading to the diagnosis of complicated Meckel's diverticulum are presented in this review. RESULTS: Complications were related to inflammation (14 patients), bleeding (5 patients), intestinal obstruction (3 patients), and penetrating foreign body (1 patient). The presence of a Meckel's diverticulum was usually suggested at CT scan by an abnormal outpouching, blind-ending digestive structure connected to the terminal ileum by a neck of variable caliber. Depending on the type of complications, the diverticulum was surrounded by mesenteric inflammatory changes, or presented as a localized fluid or air-fluid collection contiguous with the terminal ileum. The diverticulum was also the source of active bleeding or acted as the lead point to intestinal obstruction or intussusception. CONCLUSION: CT findings of complicated Meckel's diverticulum are polymorphic and should be considered in the evaluation of adult patients with acute abdomen.